Novak Djokovic is not in the business of hanging around. At this stage of a Grand Slam, the world No.1 plays with an impatience that contradicts his copious bouncing of the ball before the serve, a bundle of bristling energy that as he flings his lean frame around the tennis court.
But Djokovic would have forgiven his childhood friend for keeping him waiting in the wings of Rod Laver Arena on Friday night. As loyal to Ana Ivanovic as if she were his own sister, you can picture him fist-pumping at the screen in Rod Laver Arena's ante-room, urging Ivanovic on as she forehanded her way to the fourth round.
The two hours and 14 minutes that it took Ivanovic to beat Sam Stosur in three sets meant that Djokovic began his own quest to reach the fourth round well into the night. But, once in the heart of Rod Laver Arena, he set about his business in a splendid mood.
Beating Denis Istomin of Uzbekistan 6-3 6-3 7-5, Djokovic continued his assertive march towards a potential fifth Australian Open title, and at this rate, it will take something fairly formidable to stop him.
Istomin, famously coached by his mother Klaudiya, is capable of being just as menacing as his prescription glasses. He has two Grand Slam fourth rounds to his name, US Open 2013 and Wimbledon 2012, and counts Nicolas Almagro among his most high-profile conquests.
There is something of the Pete Sampras about the way he serves, and his flat-hitting approach suits him well on a hard court. But not against Djokovic.
The Serb soaked up all of Istomin's power and sent it back at him with interest. Breaking serve in the third game, he led 3-1 after 12 minutes, packaging up the first set 6-3 over the 26-year-old in just over half an hour.
The second set, like the first, involved just the one break of serve, Djokovic maneouvering his way ahead 4-2, and taking it by the same scoreline. The third? The same. The defending champ broke again to lead 3-1, and although Istomin brought some flashes, one particular forehand on the run that saw him vault the court's sideboards followed by a backhand winner down the line from the trams which earned him a thumbs-up from his eventual conqueror, it was not enough to rumble the Rod Laver jungle. Not properly, at least.
Changing racquets 4-3 ahead in the third, if Fabio Fognini, Djokovic's fourth-round foe, was watching, he would have seen the pyjama-suited Serb get broken as he served for the match, break straight back, and celebrate as if he'd won the title. It was the most animated Boris Becker has looked all week too.
"It was never going to be easy, Denis is a quality opponent, but in important moments I managed to stay composed. Obviously I didn't want to drop that third set and get into a fourth," Djokovic said afterwards.
"Me and my team, we are always the biggest critics for myself and my game, but I have to be satisfied. As the tournament progresses I play better and better; I have to elevate my game and it's important to stay focused and keep going.
"Fabio is a friend of mine, we grew up together, we are same generation. I know him really well, I played him the first time when we were 13, 14, we know each other's games really well. It's fourth round of Grand Slam, it's getting tougher, so there is no easy match."
Three matches into his title defence, what have we learned from Djokovic? That he is sharp, focused and determined, although not yet perfect. But make no mistake, he wants to win here again. Very much.